Climate and energy responsive housing in continental climates – the suitabiliti of passive houses fir Iran’s dry and cold climate

In spite of worldwide climate change problems caused by fossil fuel use, energy consumption levels in Iran, while already high, continue to rise each year. About 97% of the total energy consumption of Iran, and 98.8% of energy consumed by the building sector in this country is fossil fuel-derived, with residential and commercial buildings being responsible for over 40% of this amount. The present dissertation focuses on the cold climatic region in Iran, which is characterised by a continental climate, and it examines the city of Tabriz as a case study. The primary aim was to study the suitability of passive houses in Iran’s cold climatic region and to identify those architectural factors most relevant for reducing building energy consumption. Because of present economic conditions in Iran, notably the subsidised cost of fossil fuels, energy savings in buildings through expensive conservation methods are not economically viable. Thus, there is little social interest in energy saving, especially where such measures increase building costs. Therefore this thesis argues that the use of cost-neutral building methods and cheaper architectural solutions is the most realistic and pragmatic approach. This dissertation also briefly examines theoretical aspects of climate and of the effect of climatic factors on buildings, as well as examining the climatic response of various building types, passive solar heating systems and various passive and hybrid cooling methods. In addition, the work compares the energy situation, climate and residential architecture in Iran and Germany, and it introduces German concepts of energy efficient building and standards, with an emphasis on passive houses. The analysis section of dissertation is organised as follows: “Comparison of Iran and Germany” this first part of the analysis compares these two countries, with an emphasis on climatic conditions, and studies the feasibility of applying German passive house techniques and standards to Iran. In order to provide accurate and detailed results, this dissertation uses several different building energy software tools to evaluate climate data, building and system components and the economics of energy conservation. Dynamic simulation software tools and hourly weather data are also used to calculate the energy consumption of buildings. The energy software tools used in different parts of this analysis match the requirements for different stages of the research. They include EnergyPlus, DesignBuilder, Passive House Planning Package, Climate Consultant, GAEA and Economic Evaluation. “Climate data analysis” analyses the local climatic data of Tabriz, to suggest the most appropriate passive design strategies for this city. “Passive houses in Iran’s climate” simulates passive houses in Iran’s cold climatic region to suggest suitable features for passive houses and the effect of architectural design on passive house energy requirements in this region. It indicates that not only are passive houses climatically suitable for winter conditions in this region, but that they are also more easily achievable, requiring less insulation. However, they do need additional cooling systems. “Simulation of subsoil heat exchanger” shows the energy saving potential and economic efficiency of subsoil heat exchangers in Iranian passive houses. To present a simulation of different architectural factors and building elements, “Simulation of architectural elements” searches for the optimal case and the most appropriate application of each of these factors and elements under given conditions. An analysis of the simulations provided in this section shows the behaviour of energy efficiency in relation to different measures or quantities of various architectural factors and building elements. This section offers an explanation and rationalisation of the complex relationships between building energy use and architectural design. “Simulation of Buildings with different Architectural Designs” simulates and compares the energy consumption of a typical building with some other newly designed buildings. The energy demand of the most efficient building is 63% less than the least efficient building available in similar control conditions, but with architectural design as the only variable. This shows that architectural design profoundly affects heating, cooling and therefore the total energy consumption of buildings. This section introduces those architectural factors which reduce the energy consumption of buildings in Iran’s cold climatic region. There is a big difference in the construction costs (about 50%) for passive and non-passive houses in Iran. Nonetheless, based on the economic evaluation done in “Economic Analysis”, if the passive houses have an energy efficient architectural design, the use of these kinds of buildings is economically very viable when based on international energy costs. However, in view of current subsidisation of fuel, investment for passive houses in Iran is economically not viable at present. The section “Mechanical Equipment” outlines specifications for heating and cooling equipment which is climatically, economically and technologically appropriate for energy efficient and passive housing in Iran. Gas heat pumps can be integral to mechanical systems for heating and cooling both energy efficient houses and passive houses in Iran. Heater-cooler unit systems are also particularly suitable in this country. In Iran’s cold climatic region, the energy consumption of a well-insulated, suitably-designed building is only 8.3% of an uninsulated normal house, so the potential for energy saving in buildings is very high. Therefore, to solve this problem the present research strongly suggests using both architectural techniques and insulation materials.